Generally, in industrial robots having a base body and a movable body pivotably provided thereon, the power cable, signal cable, etc. are led into the movable body through the interior of the base body. As the movable body is pivoted, the cables are moved in that pivoting direction. Therefore, there should be normally housed in the base body a length of cables large enough to ensure smooth movement of the movable body.
Referring now to FIGS. 1 and 2, a conventional industrial robot has a body base with a cylindrical inner surface and having a guide cone 2 provided concentrically therein. A movable body 3 is pivotably provided atop the base body 1. A cable 4 led into the movable body 3 through the interior of the base body 1 is wound about one turn about the guide cone 2. Usually, a plurality of power and signal cables (not shown for simplicity of the illustration) is housed in the base body in a similar manner.
In the case of such conventional industrial robots, the cable 4 is freely movable in the space defined between the inner wall of the base body 1 and the guide cone 2, so the cable 4, inner wall of the base body 1 and the guide cone 2 rub against each other. In this way, the surface of the cable 4 is likely to be abraded. Also, where plural cables are housed inside the base body 1, they entwine with each other and are bent beyond their bending limits, possibly resulting in damage to them.